Collapsible form



March 16, 1937. H, c. BosTwlcK coLLAPsIBLE FORM l Filed July 16, 1936 Patented Mar. 16, 1937 UNITED STATES PATENT OFFICE COLLAPSIBLE FORM Application July 16, 1936, Serial No. 90,958

11 Claims.

as considerably to reduce the extent of collapse.

The present invention avoids this diiculty by l an improved arrangement of detachable beadseating anges.

Of the accompanying drawing, Fig. 1 is a rear elevation, in section through the shaft, of a tirebuilding drum provided with detachable bead flanges in accordance with my invention.

Fig. 2 is a longitudinal section, approximately on the line 2-2 of Fig. l.

Fig. 3 isa fragmental elevation showing'tl'ieV collapsed relation of adjoining ange segments and separation of their pivotal connection.

Fig. 4 is a fragmental edge view of adjoining .flange segments showing a modified pivotal connection.A

The drawing illustrates this invention as applied to a drum of the general type disclosedin my Patent No. 2,042,498 of June 2, 1936. I0 is a horizontal rotary power shaft to which is fixed a central segment support or spider II consisting of a hub and a pair of opposite arms. To the ends of these arms, on hinge pins I2, are pivoted two pairs of chuck body segments comprising duplicate members I3 with underlapping ends and duplicate members I4 with overlapping ends meeting those of the. segments I3 in expanded condition, said segments being arranged in couples, with oppositely swinging members. To opcrate the segments, there is provided the usual toggle control including a sleeve or collar I5 concentric with the shaft and rotatable with or relative thereto at the end of a hollow shaft I6, a pair of 'short links I1 connected with the 'underv lapping segments I3 and forming, with arms on said collar, a, pair of toggles whichrefnot fully straightened in the expanded position, and a pair of longer bent links I8 forming another pair of toggles with said collar, the knuckle pins of which pass over center in reaching the expanded condition. When the collar I5 and hollow shaft i I6 are retarded while the drum is forwardly rotating, as by means of a brake (not shown), the toggles will fold and collapse the drum by its power of rotation. It is also common to collapse such drums by a hand-wheel. Reverse rotation of the drum while the control collar is held will 5 expand the drum, and it may also be automatically expanded by centrifugal force when rotated in either direction. It will be understood that the invention may also be applied to other types of drums. i l0 This illustrated drum has the usual widthwise adjustment, being formed with body segments ISLhingedto the spider and connected with the toggle links, wing. segments 20 adjustably fixed thereon by screws 2| whose stems occupy slots l5 22 in the body segments, and thin gap-shield segments 23 aflixed to a central at rib structure on the body segments. 4

In the preferred 'embodiment of my invention here illustrated, there is removably mounted in 20 each end of the drumI body. which includes the base andwing segments, a segmental collapsible bead-seating ange or ring 24 having a short cylindrical portion 25 flush with the cylindrical outer surface of the adjacent wing segment 20, 25 a rounded shoulder portion 26, an undercut beadseatingil portion 21, and an inner marginal radial portion 28. Said bead ring also has an axially extending mounting flange 29 fitted and locked against outward radial movement within the 30 marginal portion of the wing segment, and interlocked therewith against axial movement by a circumferential rib 30 on the ring ange occupying 'a complementa] groove 3| on the wing segment. A slanting inward movement of the bead ring segments, to clear each'of them from the tire beads when the ring is to be removed, is provided for by forming interfltting male and female cones 32 and 33, parallel with the bead seat 21,fon the ring and wing segment respectively, and forming 4 the end of the base segment I3 with a corresponding-undercut bevel 34.

Each of the bead rings 24 is transversely divided into segments, preferably unequal inl num- 45 ber and/or angular length to the drum body segments so as to break joints therewith, said ring Vsegments in this case being three in number including a key segment 35, an intermediate segment 36 and a last segment 31. -Radial joints 36 and 39 are formed between the respective pairs 35, 36 and 36. 31, and a semitangent joint 440, with a curved underlapping surface on the key segment and a complemental overlapping surface on the last segment, both concentric with the pivot of said key segment, is formed between these two. At the joint 40 there is provided any suitable form of spring lock or latch, such as a slidable bolt 4I carried by the key segment 35 and yieldingly pressed by a spring 42 into a socket 43 in the last segment 31. On swinging the key segment outwardly into its operative position, this latch will automatically lock together the ends of the segments 35 and 31 against the pressure of the stitching tools as they round the shoulders of the drum, and to release the latch, it may be manually withdrawn by pulling on the head at its inner end.

The respective pairs of segments 35, 36 and 36, 31 are pivotally connected in end-to-end relation at their inner periphery by means oi' an ear 44 on the posterior one of said segments (such as 36 for the pair 35, 36), an axially extending pivot stud screwed into said earand formed with a head 46 at its inner end, and an adjacent ear 41 lying inwardly of the ear 44 and movable both pivotally of said stud 45 to swing-the anterior segment into an angular relation with the posterior one, and axially of the stud, to allow a bead clearlngmovement of the ring segment inwardly of the drum in an axial direction, the combined movement being a slanting one permitted by the beveled surfaces 32, 33 and 34. Ear 41 is also formed with a slot or open-sided bearing recess 48 which, when the segments are circumferentially aligned, is semitangently slanted outwardly in a direction toward the adjoining segment so as normally to lock the pivot joint against inward radial separation of the anterior segment fromthe posterior one, but adapted to permit such separation as shown in Fig. 3 when the anterior segment, such as 35, is swung thrmgh a sufcient angle to move the sides of the slot to or beyond a position of parallelism with the radial joint 38.

In the operation of this invention, when the drum body has been expanded into a circle as shown in Figs. 1 and 2, the bead ring segments 35, 36 and 31 may be connected end-to-end and successively assembled in said body and interlocked with the wing segments 20 by means of the rib 30 and groove 3|, by placing first the segment 31, then 36 and finally 35, which will be interlocked by the latch bolt 4I with the segment 31 as the key segment 35 is swung outwardly into position. Each of the bead rings 24 is preferably in an indeterminate angular relation with the drum body, being placeable in any rotative position with respect to said body, toA simplify the structure and save time in its assembly. The presence of these bead rings lends radial support to the body segments I3 and I4, supplementing the action of the toggles in avoiding any unintended collapse of the drum, and acting to hold the ends of the drum-body segments in alignment. When the tire band is completed, the rings 24 are removed, one segment at a time, beginning with the key segment35, and in the course of their removal, afterfunseating the segment from the drum body, it may be turned endwise into an interior space of the drum before its removal through' the central aperture of the beadon that side. On removal of both bead rings, the drum body may then be collapsed in the usual manner,

either by hand or by the power o'f its rftation,

through retardation of the control collar I5.

Fig.` 4 represents a moditled pivotal connection between adjoining bead ring segments such as an anterior key segment 35 and a posterior intermediate segment 36, according to which the hinge ears 44a and41 on the respective SegmntS are connected by a hinge stud or pin 45'L wh'ose axis is slantingly disposed at an angle to the drum axis so that a collapsing swinging movement of the anterior segment will be in an approximately helical direction inwardly of the drum to aid in clearing said segment from the adjacent tire bead. This pivot joint may be made separable as previously described, to allow individual removal of the segments.

It will be understood that other changes of embodiment may be made. For example, Awhile itis preferred to make the bead flanges as full-depth rings detachable from the drum body at the latters outer periphery, to permit the greatest extent of collapse of said body, the invention is not Wholly restricted to such an arrangement.

I claim:

1. A tire-building form comprising a collapsible, segmental form body, and an independently collapsible segmental, bead-seating flange structure removably mounted thereon and composed of segments detachable by moving them radially inward from the form body.

2. A tire-building form comprising a collapsible, segmental form body, and a collapsible beadseating ring removably mounted thereon and composed of a-series of segments Whose adjoining members. are pivotally connected with each other, interlocking with the form body by an outward radial movement:

3. A tire-band building drumv comprising a collapsible, segmental, substantially cylindrical drum body, and a pair of-undercut bead-seating rings removably mounted in the ends of said body and forming the substantially cylindrical end portions of the outer periphery of the drum, said rings being composed of segments and inwardly collapsible for removal from the drum body.

4. A tire-building drum comprising a central rotary segment support, a collapsible drum body permanently mounted thereon and composed oi' pivoted segments, and a pair of collapsible, segmental, bead-seating rings removably locked in abutting surfaces adapted to permit a slanting inward separating movement of said ring radially and axially of the form.

' 6. A tire-building form according to claim 5 in which the ring is formed with an undercut bead-seating portion, and it Aand the ring-abutting surfaces of said form are beveled to allow a slanting separating movement oi' said ring inwardly of the form.

7. A tire-building form comprising a. radiallycollapsible, segmental form, body, and a beadseating ring detachably mounted thereon and composed of segmentsl separable connected in series, and detachable from the form body by an inward radial movement.

8. A tire-building form according to claim 'I in which the segments are connected by separable pivot joints permitting the individual removal of the segments while the body segments remain expanded in the tire band.

9. A tire-building form .comprisingv a collapsiseating ring detachably mounted thereon and composed of vsegments plvotally connected ln series and having pivotal and axial collapsing movements inwardly of the form to clear them Y of the tire beads.

10. A tire-building -form according to claim 9 in which the pivot joint between a pair o! ring segments includes an axially extending pivotpin on one segment and an ear on'the other segment HENRY C. BOSTWICK. 

